研究了影响一类重要的氨基烷基自由基对丙烯酸酯双键的加成反应的反应性的主要因素。相互作用的速率常数,通过使用激光诱导光声量热法直接测量,范围从 2.5 x 10(7) 到 4.5 x 10(7) M(-)(1) s(-)(1)。将这些自由基的反应性与烷基自由基的反应性进行比较。计算表明反应焓不是驱动因素。过渡态的分子轨道计算清楚地证明了电荷转移构型相对于非极性构型的大量参与,导致势垒高度的降低。此外,当绘制过渡态中的电荷转移特性与电离电位时,发现了非常好的相关性。
Acrylate radicals: Direct observation and reactivity
作者:Jacques Lalevée、Xavier Allonas、Jean Pierre Fouassier
DOI:10.1016/j.cplett.2005.08.152
日期:2005.11
for the direct study of the chemical reactivity of acrylate radicals is developed: the acrylate radicals are produced by the addition of an aminoalkyl radical to an acrylate double bond and directly observed by transient absorption spectroscopy. These acrylate radicals are characterized by a strong absorption in the visible part of the spectrum allowing to easily probe their chemical reactivity. This
The major factors affecting the reactivity of the important class of aminoalkyl radicals toward the addition reaction onto acrylate doublebonds were studied. The rate constants of interaction, directly measured by using laser-induced photoacoustic calorimetry, range from 2.5 x 10(7) to 4.5 x 10(7) M(-)(1) s(-)(1). The reactivity of these radicals was compared to that of alkyl radicals. Calculations
研究了影响一类重要的氨基烷基自由基对丙烯酸酯双键的加成反应的反应性的主要因素。相互作用的速率常数,通过使用激光诱导光声量热法直接测量,范围从 2.5 x 10(7) 到 4.5 x 10(7) M(-)(1) s(-)(1)。将这些自由基的反应性与烷基自由基的反应性进行比较。计算表明反应焓不是驱动因素。过渡态的分子轨道计算清楚地证明了电荷转移构型相对于非极性构型的大量参与,导致势垒高度的降低。此外,当绘制过渡态中的电荷转移特性与电离电位时,发现了非常好的相关性。